The present invention relates generally to an improved fluid power cylinder, and more particularly, to a fluid power cylinder of the type having a cylinder with an elongated slot, a piston reciprocally movable within the cylinder and an improved strip sealing means for successively sealing the slot during movement of the piston.
Power cylinders, and in particular pressure fluid power cylinders, have existed in the art for many years. In general, a pressure fluid power cylinder includes an elongated cylinder and a piston member disposed therein for reciprocal back and forth movement along the length of the cylinder. Such movement is controlled by the introduction of hydraulic or pneumatic fluid pressure into the chambers at the ends of the cylinder on each side of the piston element. Such power cylinders also include means for transferring the reciprocal movement of the piston to an external workpiece. One type of power cylinder is a cable cylinder which includes a cable connected to opposite ends of the piston and extending around pulleys at the cylinder ends to transfer the force to the workpiece. A second type of fluid cylinder is the type illustrated in U.S. Pat. No. 3,820,446. In this type of cylinder, the bracket for transferring the force from the reciprocating piston to the workpiece is connected directly with the piston element. This connection is through an elongated slot disposed about the entire length of the cylinder element. Because of this elongated slot in the cylinder element, an elongated strip or band seal is needed to seal the pressure chambers in the opposite ends of the cylinder to prevent the pressure fluid from escaping through the slot.
While many of the prior art fluid power cylinders perform satisfactorily in certain applications, there continue to be ways in which such power cylinders can be improved. For example, with power cylinders of the type having a cylinder with an elongated slot, a reciprocally movable piston and a strip sealing member, efforts are continually being made to improve the sealing relationship between the strip seal and cylinder, to increase the life and wearability of the seal and cylinder and to develop cylinders of different sizes and for various applications. Thus, a need continues to exist in the art for a cylinder having the above mentioned improvements and flexibility.